Fluid-translating device.



H. F. SCHMIDT.

FLUID TRANSLATING DEVICE.

APPLICATION FILED SEPT. 14. 1914.

Patented Apr; 9, 1918.

H/S ATTORNEY IN FACT rrrr sArs A HENRY r. SCHMIDT, or PITTSBURGH,PENNSYLVANIA, ASSIGNOR T0 WESTINGHOUSE ELECTRIC & MANUFACTURING COMPANY,A CORPORATION or PENNSYLVANIA.

FLUID-TRANSLATING DEVICE.

Specification of Letters Patent.

Patented Apr. 9, 1918.

To all whom it may concern:

Be it known that I, HENRY F. SCHMIDT, a citizen of the United States,and a resident of Pittsburgh, in the county of Allegheny and State ofPennsylvania, have made a new and useful Invention in Fluid-TranslatingDevices, of which the following is a specification.

This invention relates to fluid translating devices, such, for example,as ejectors, in which the kinetic or velocity energy of the motive fluidis employed in exhausting fluid from a receptacle to be evacuated, or incompressing a fluid from a region of lower to a region of higherpressure.

In ejectors employing diflusers for build ing up pressure by convertingkinetic into potential or pressure energy, pulsations in the mediumtraversing the difluser occur for various reasons. If these pulsationsare of sufficient magnitude that the loss occasioned by shock results ina sufficient diminution of the velocity of the medium, and consequentlyof the available kinetic energy, so that the energy is reduced belowthat necessary to overcome the external or discharge pressure, thevelocity in the diffuser will instantly fall to zero. This will reducethe expelling force to zero and consequently occasion a flow in thereverse direction or from the outlet of the diffuser back into theregion of lower pressure.

An object of this invention is, therefore, to produce an ejector inwhich means are employed for preventing pressure oscillations in thediffuser from becoming large enough to detrimentally affect theoperation of the ejector.

A further object of the invention is to produce a fluid translatingdevice, of the kinetic type, in which means are employed for maintainingthe operation of the device substantially constant for practically allvarying conditions.

A. still further object is to produce a fluid translating deviceemploying the kinetic or velocity energy, of the motive fluid deliveredto it, in transferring fluid from a region of lower to a region ofhigher pressure, which automatically adjusts itself to variations in thequantity of fluid conveyed, thus preventing fluctuations of pressure ineither the region of higher or lower pressure.

These and other objects, which Wlll be made apparent to those skilled inthe art throughout the further description of the invention, areattained by apparatus embodying the features herein described andillustrated in the drawing accompanying and forming a part of thisapplication.

In the single sheet drawing I have shown, more or less diagrammatically,a sectional view of an ejector embodying my inveir tion.

The ejector illustrated comprises a combining or suction chamber 9,which is provided with an inlet port 2, nozzles 4 for discharging fluidfrom a source of fluid pressure through the combining or suction chamber9 into a diffuser 3, through which the combined media discharged fromthe combining chamber 9 are discharged from the lower to the higherpressure through the outlet 7 of the diffuser u.

The difiuser 3 has fitted near its outlet one or more well roundedconical nozzles S pointing in the direction of normal flow of the mediathrough the difl'user 3. This nozzle, or nozzles, is provided so topermit the passage of fluid only through the opening and not around theedges of the diffuser. The cross-sectional area of the diffuser is sodesigned that subtantia-lly all the kinetic energy in'the fluid enteringthe diffuser is transformedinto the work of translation before reachingthe first of the nozzles 8.

The nozzles 8 are so contracted that there is a slight drop of pressurethroughthem to the discharge of the diffuser 7. Thus the diffuser 3 willcompress or move the medium discharged from the nozzles a and entrainedin the chamber 9 against a pressure slightly higher than at the outletof the difluser 7.

It is a well known law of hydraulics and thermodynamics that thecoefiicient of flow through a well rounded orifice is essentially unity,and also that the coefficient of flow through an open ended tubeprojecting into the medium discharging into it is approximately 27/100of the flow through a well rounded orifice. The result is that with anarrangement of the nozzle or nozzles 8 such as disclosed, the flow inthe normal direction will occur with approximately only one-half thedrop of pressure through the nozzle or nozzles 8 as is required to causea flow in the opposite direction. i

It is well known that harmonic oscilla- 'tions, such as the shockvibrations set up in fluids under certain conditions, can only bepropagated-or incre'a sed in magnitude through resonance 'so' long asthe resistance Which is overcome by the wave formation is equal in bothdirections longitudinally of the Wave motion. It will be evident, therefore, thatin the arrangement shown, resonance is prevented,and shockvibrations tending to be set up, due to the passing ofa-quantityfotmedium, other than for'wvhich the diffuser was designed,will be prevented from attaining a magnitude sufiicient to cause a greatenougl'i' loss of kinetic energy that. breaking down will occur. Bybreaking down I mean an equalization of the pressures at the outlet 7and in the chamber 9, or momentary fluctuations of pressure in thediffuser occasioned by conditions other than variations in the deliveryof fluid by the nozzles st or variations in the amount of me diumentering the chamber 9.

While I have illustratedbut one embodiment of my invention,'it will beapparent to those skilled in the art, that the drawing is merel'illustratix e, and that various changes, modifications, substitutions,additions and omissions may be made in the apparatus illustrated Withoutdeparting from the spirit and scope of my invention as set forth by theappended claims.

What I claimis:

1. In an ejector, a suction chamber, a dif fuser'communicatingtherewith, a nozzle for delivering expelling medium through thediffuser, and a plurality of con-verging nozzles' of pro gressivelyincreasing area located at the-dischargeend of the effective portion ofthe-diffuser, pointing in the direction offlow through the diffuser andpassing all of fthe fluid 'issuing from the diffuser.

2' In an ejecting device, a chamber to which medium to be expelled isdelivered, a diffuser communicating therewith, and through which themedium is expelled, a nozzle for delivering expelling medium through thediffuser, and a converging nozzle extending across the outlet of theeffective portion of the diffuser, converging in the direction of thenormalflow of medium, and passing-all the fluid issuing from thediffuser;

3. In an ejecting device, a chamber to which fluid to "be exp'elled' isdelivered, a diffuser communicating therewith, and through which thefluid is expelled, means for delivering a stream of expelling fluidthrough said diffuser, and a Well rounded nozzle, located at the end ofthe effective portion of the diffuser, pointing in'the direction "offlow through the diffuser, and

passing allot the fluid issuing from the diffuses.

i In'an ejecting device, a chamber to which medium to be expelled isdelivered,

. a diffuser? communicating therewith-, and;

the effective portion of the diffuser and offering a greater resistanceto flow ina direction oppositeto the normal flow than'in the directionof the normal flow through the ejector. V I

6. In combination with an ejector, means located atthe outlet of theeffective portion of the diffuser for preventing upsetting, comprisingWell rounded nozzles of successively increasing area and "with theiroutlets pointing in the direction of flow through the diffuser.

7. In an apparatus of the characterde- V scribed, a chamber from Whichmedium is to be exhausted, a diffuser communicating therewith, andthrough Which medium is expelled, means for delivering expelling fluidthrough the'diffuser, and means located Within the diffuserfor dampeningharmonic Wavespropagated'in-the diifuser.

8. In an apparatus'of the character described, a chamber from avhichmedium is to be exhausted, a di'liuser'communicating therewith, andthrough which medium is" expelled, means for discharging an ex pellingmediumthrough said difiuser, and means comprising a plurality ofconverging nozzles located at the discharge end ofthe effective portionof the diffuser and of successively increasing area.

9. In an apparatus of the character described, a chamber from whichmedium is to be exhausted, having a medium inlet and a medium outletport, means for discharging expelling fluid throughthe outlet port ofsaid chamber, a difluser communicating with the outlet port and aplurality of valveless orifices intercepting the diffuser and offering agreaterresistance to'flow in one direction than in the other.

In testimony whereof, I have hereunto subscribed .my name this 21st dayof August,

G; W. l\IoGHEE,- E. W. MCCALLISTER.

Coislfofthii iietht inay beobtaine'd"ior 'five'cents each, by addressingthe Commissioner of Patents,

Washington, D. C.

